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JavaScript prototype Property : Date Object

Description

The prototype property is used to add new properties and methods to a date object.

Version

Implemented in JavaScript 1.1

Syntax

myobj.prototype.name = value 

myobj: The name of the constructor function object you want to change.

name: The name of the property or method to be created.

value: The value initially assigned to the new property or method.

If you add a property to the prototype for an object, then all objects created with that object's constructor function will have that new property, even if the object existed before you created the new property.

Example:

In the following web document, we add a method to the date object which returns the month name of current date.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title>JavaScript date Object - prototype Property example</title>
<script type="text/javascript">
//This is done to make the following JavaScript code compatible to XHTML. <![CDATA[
function monthstring()
{
var mname
switch(this.getMonth())
{
case 0:
mname="January";
break;
case 1:
mname="February";
break;
case 2:
mname="March";
break;
case 3:
mname="April";
break;
case 4:
mname="May";
break;
case 5:
mname="June";
break;
case 6:
mname="July";
break;
default:
case 7:
mname="August";
break;
case 8:
mname="September";
break;
case 9:
mname="October";
break;
case 10:
mname="November";
break;
case 11:
mname="December";
break;
mname="Invalid mname";
}
return(mname);
}
//]]>
</script>
</head>
<body>
<h1 style="color: red">JavaScript date object : prototype property</h1>
<hr />
<script type="text/javascript">
//This is done to make the following JavaScript code compatible to XHTML. <![CDATA[
Date.prototype.monthname = monthstring;
var a = new Date();
var b = a.monthname();
document.write("Current Month is : "+b); 
//]]>
</script>
</body>
</html>

View the example in the browser

Supported Browser

Internet Explorer 7 Firefox 3.6 Google Chrome 7 Safari 5.0.1 Opera 10
Yes Yes Yes Yes Yes

See also:

JavaScript Core objects, methods, properties.

Previous: JavaScript constructor Property: Date Object
Next: JavaScript getDate() Method: Date Object

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